A cochlear fenestration burr is a specialized surgical drill for use in drilling a hole or fenestration in the otic capsule bone adjacent to the scala tympani of the cochlea. Existing surgical drills are used by otologists to fenestrate the cochlea for the purpose of inserting an electrode that is part of a cochlear implant. In the case of such a cochlear implant there is little concern about damaging the internal structures of the cochlea while drilling because inserting the electrode will cause damage in any event. Accordingly the existing fenestration burrs have no guard or drill stop of any sort.
For fully implantable hearing aids, it is important when fenestrating the cochlea not to damage the basilar membrane or organ of corti. Accordingly, a different approach to fenestration burrs will be required.